QFileInfo(3qt)QFileInfo(3qt)NAME
QFileInfo - System-independent file information
SYNOPSIS
All the functions in this class are reentrant when Qt is built with
thread support.</p>
#include <qfileinfo.h>
Public Members
enum PermissionSpec { ReadOwner = 04000, WriteOwner = 02000, ExeOwner =
01000, ReadUser = 00400, WriteUser = 00200, ExeUser = 00100,
ReadGroup = 00040, WriteGroup = 00020, ExeGroup = 00010, ReadOther
= 00004, WriteOther = 00002, ExeOther = 00001 }
QFileInfo ()
QFileInfo ( const QString & file )
QFileInfo ( const QFile & file )
QFileInfo ( const QDir & d, const QString & fileName )
QFileInfo ( const QFileInfo & fi )
~QFileInfo ()
QFileInfo & operator= ( const QFileInfo & fi )
void setFile ( const QString & file )
void setFile ( const QFile & file )
void setFile ( const QDir & d, const QString & fileName )
bool exists () const
void refresh () const
bool caching () const
void setCaching ( bool enable )
QString filePath () const
QString fileName () const
QString absFilePath () const
QString baseName ( bool complete = FALSE ) const
QString extension ( bool complete = TRUE ) const
QString dirPath ( bool absPath = FALSE ) const
QDir dir ( bool absPath = FALSE ) const
bool isReadable () const
bool isWritable () const
bool isExecutable () const
bool isHidden () const
bool isRelative () const
bool convertToAbs ()
bool isFile () const
bool isDir () const
bool isSymLink () const
QString readLink () const
QString owner () const
uint ownerId () const
QString group () const
uint groupId () const
bool permission ( int permissionSpec ) const
uint size () const
QDateTime created () const
QDateTime lastModified () const
QDateTime lastRead () const
DESCRIPTION
The QFileInfo class provides system-independent file information.
QFileInfo provides information about a file's name and position (path)
in the file system, its access rights and whether it is a directory or
symbolic link, etc. The file's size and last modified/read times are
also available.
A QFileInfo can point to a file with either a relative or an absolute
file path. Absolute file paths begin with the directory separator "/"
(or with a drive specification on Windows). Relative file names begin
with a directory name or a file name and specify a path relative to the
current working directory. An example of an absolute path is the string
"/tmp/quartz". A relative path might look like "src/fatlib". You can
use the function isRelative() to check whether a QFileInfo is using a
relative or an absolute file path. You can call the function
convertToAbs() to convert a relative QFileInfo's path to an absolute
path.
The file that the QFileInfo works on is set in the constructor or later
with setFile(). Use exists() to see if the file exists and size() to
get its size.
To speed up performance, QFileInfo caches information about the file.
Because files can be changed by other users or programs, or even by
other parts of the same program, there is a function that refreshes the
file information: refresh(). If you want to switch off a QFileInfo's
caching and force it to access the file system every time you request
information from it call setCaching(FALSE).
The file's type is obtained with isFile(), isDir() and isSymLink(). The
readLink() function provides the name of the file the symlink points
to.
Elements of the file's name can be extracted with dirPath() and
fileName(). The fileName()'s parts can be extracted with baseName() and
extension().
The file's dates are returned by created(), lastModified() and
lastRead(). Information about the file's access permissions is obtained
with isReadable(), isWritable() and isExecutable(). The file's
ownership is available from owner(), ownerId(), group() and groupId().
You can examine a file's permissions and ownership in a single
statement using the permission() function.
If you need to read and traverse directories, see the QDir class.
See also Input/Output and Networking.
Member Type Documentation
QFileInfo::PermissionSpec
This enum is used by the permission() function to report the
permissions and ownership of a file. The values may be OR-ed together
to test multiple permissions and ownership values.
QFileInfo::ReadOwner - The file is readable by the owner of the file.
QFileInfo::WriteOwner - The file is writable by the owner of the file.
QFileInfo::ExeOwner - The file is executable by the owner of the file.
QFileInfo::ReadUser - The file is readable by the user.
QFileInfo::WriteUser - The file is writable by the user.
QFileInfo::ExeUser - The file is executable by the user.
QFileInfo::ReadGroup - The file is readable by the group.
QFileInfo::WriteGroup - The file is writable by the group.
QFileInfo::ExeGroup - The file is executable by the group.
QFileInfo::ReadOther - The file is readable by anyone.
QFileInfo::WriteOther - The file is writable by anyone.
QFileInfo::ExeOther - The file is executable by anyone.
Warning: The semantics of ReadUser, WriteUser and ExeUser are
unfortunately not platform independent: on Unix, the rights of the
owner of the file are returned and on Windows the rights of the current
user are returned. This behavior might change in a future Qt version.
If you want to find the rights of the owner of the file, you should use
the flags ReadOwner, WriteOwner and ExeOwner. If you want to find out
the rights of the current user, you should use isReadable(),
isWritable() and isExecutable().
MEMBER FUNCTION DOCUMENTATIONQFileInfo::QFileInfo ()
Constructs a new empty QFileInfo.
QFileInfo::QFileInfo ( const QString & file )
Constructs a new QFileInfo that gives information about the given file.
The file can also include an absolute or relative path.
Warning: Some functions might behave in a counter-intuitive way if file
has a trailing directory separator.
See also setFile(), isRelative(), QDir::setCurrent(), and
QDir::isRelativePath().
QFileInfo::QFileInfo ( const QFile & file )
Constructs a new QFileInfo that gives information about file file.
If the file has a relative path, the QFileInfo will also have a
relative path.
See also isRelative().
QFileInfo::QFileInfo ( const QDir & d, const QString & fileName )
Constructs a new QFileInfo that gives information about the file called
fileName in the directory d.
If d has a relative path, the QFileInfo will also have a relative path.
See also isRelative().
QFileInfo::QFileInfo ( const QFileInfo & fi )
Constructs a new QFileInfo that is a copy of fi.
QFileInfo::~QFileInfo ()
Destroys the QFileInfo and frees its resources.
QString QFileInfo::absFilePath () const
Returns the absolute path including the file name.
The absolute path name consists of the full path and the file name. On
Unix this will always begin with the root, '/', directory. On Windows
this will always begin 'D:/' where D is a drive letter, except for
network shares that are not mapped to a drive letter, in which case the
path will begin '//sharename/'.
This function returns the same as filePath(), unless isRelative() is
TRUE.
If the QFileInfo is empty it returns QDir::currentDirPath().
This function can be time consuming under Unix (in the order of
milliseconds).
See also isRelative() and filePath().
Examples:
QString QFileInfo::baseName ( bool complete = FALSE ) const
Returns the base name of the file.
If complete is FALSE (the default) the base name consists of all
characters in the file name up to (but not including) the first '.'
character.
If complete is TRUE the base name consists of all characters in the
file up to (but not including) the last '.' character.
The path is not included in either case.
Example:
QFileInfo fi( "/tmp/archive.tar.gz" );
QString base = fi.baseName(); // base = "archive"
base = fi.baseName( TRUE ); // base = "archive.tar"
See also fileName() and extension().
bool QFileInfo::caching () const
Returns TRUE if caching is enabled; otherwise returns FALSE.
See also setCaching() and refresh().
bool QFileInfo::convertToAbs ()
Converts the file's path to an absolute path.
If it is already absolute, nothing is done.
See also filePath() and isRelative().
QDateTime QFileInfo::created () const
Returns the date and time when the file was created.
On platforms where this information is not available, returns the same
as lastModified().
See also lastModified() and lastRead().
QDir QFileInfo::dir ( bool absPath = FALSE ) const
Returns the file's path as a QDir object.
If the QFileInfo is relative and absPath is FALSE, the QDir will be
relative; otherwise it will be absolute.
See also dirPath(), filePath(), fileName(), and isRelative().
Example: fileiconview/qfileiconview.cpp.
QString QFileInfo::dirPath ( bool absPath = FALSE ) const
Returns the file's path.
If absPath is TRUE an absolute path is returned.
See also dir(), filePath(), fileName(), and isRelative().
Example: fileiconview/qfileiconview.cpp.
bool QFileInfo::exists () const
Returns TRUE if the file exists; otherwise returns FALSE.
Examples:
QString QFileInfo::extension ( bool complete = TRUE ) const
Returns the file's extension name.
If complete is TRUE (the default), extension() returns the string of
all characters in the file name after (but not including) the first '.'
character.
If complete is FALSE, extension() returns the string of all characters
in the file name after (but not including) the last '.' character.
Example:
QFileInfo fi( "/tmp/archive.tar.gz" );
QString ext = fi.extension(); // ext = "tar.gz"
ext = fi.extension( FALSE ); // ext = "gz"
See also fileName() and baseName().
Example: qdir/qdir.cpp.
QString QFileInfo::fileName () const
Returns the name of the file, excluding the path.
Example:
QFileInfo fi( "/tmp/archive.tar.gz" );
QString name = fi.fileName(); // name = "archive.tar.gz"
See also isRelative(), filePath(), baseName(), and extension().
Examples:
QString QFileInfo::filePath () const
Returns the file name, including the path (which may be absolute or
relative).
See also isRelative() and absFilePath().
Examples:
QString QFileInfo::group () const
Returns the group of the file. On Windows, on systems where files do
not have groups, or if an error occurs, QString::null is returned.
This function can be time consuming under Unix (in the order of
milliseconds).
See also groupId(), owner(), and ownerId().
uint QFileInfo::groupId () const
Returns the id of the group the file belongs to.
On Windows and on systems where files do not have groups this function
always returns (uint) -2.
See also group(), owner(), and ownerId().
bool QFileInfo::isDir () const
Returns TRUE if this object points to a directory or to a symbolic link
to a directory; otherwise returns FALSE.
See also isFile() and isSymLink().
Examples:
bool QFileInfo::isExecutable () const
Returns TRUE if the file is executable; otherwise returns FALSE.
See also isReadable(), isWritable(), and permission().
bool QFileInfo::isFile () const
Returns TRUE if this object points to a file. Returns FALSE if the
object points to something which isn't a file, e.g. a directory or a
symlink.
See also isDir() and isSymLink().
Examples:
bool QFileInfo::isHidden () const
Returns TRUE if the file is hidden; otherwise returns FALSE.
On Unix-like operating systems, including Mac OS X, a file is hidden if
its name begins with ".". On Windows a file is hidden if its hidden
attribute is set.
bool QFileInfo::isReadable () const
Returns TRUE if the file is readable; otherwise returns FALSE.
See also isWritable(), isExecutable(), and permission().
Example: distributor/distributor.ui.h.
bool QFileInfo::isRelative () const
Returns TRUE if the file path name is relative. Returns FALSE if the
path is absolute (e.g. under Unix a path is absolute if it begins with
a "/").
bool QFileInfo::isSymLink () const
Returns TRUE if this object points to a symbolic link (or to a shortcut
on Windows, or an alias on Mac OS X); otherwise returns FALSE.
See also isFile(), isDir(), and readLink().
Examples:
bool QFileInfo::isWritable () const
Returns TRUE if the file is writable; otherwise returns FALSE.
See also isReadable(), isExecutable(), and permission().
Example: distributor/distributor.ui.h.
QDateTime QFileInfo::lastModified () const
Returns the date and time when the file was last modified.
See also created() and lastRead().
Example: biff/biff.cpp.
QDateTime QFileInfo::lastRead () const
Returns the date and time when the file was last read (accessed).
On platforms where this information is not available, returns the same
as lastModified().
See also created() and lastModified().
Example: biff/biff.cpp.
QFileInfo & QFileInfo::operator= ( const QFileInfo & fi )
Makes a copy of fi and assigns it to this QFileInfo.
QString QFileInfo::owner () const
Returns the owner of the file. On systems where files do not have
owners, or if an error occurs, QString::null is returned.
This function can be time consuming under Unix (in the order of
milliseconds).
See also ownerId(), group(), and groupId().
uint QFileInfo::ownerId () const
Returns the id of the owner of the file.
On Windows and on systems where files do not have owners this function
returns ((uint) -2).
See also owner(), group(), and groupId().
bool QFileInfo::permission ( int permissionSpec ) const
Tests for file permissions. The permissionSpec argument can be several
flags of type PermissionSpec OR-ed together to check for permission
combinations.
On systems where files do not have permissions this function always
returns TRUE.
Example:
QFileInfo fi( "/tmp/archive.tar.gz" );
if ( fi.permission( QFileInfo::WriteUser | QFileInfo::ReadGroup ) )
qWarning( "I can change the file; my group can read the file" );
if ( fi.permission( QFileInfo::WriteGroup | QFileInfo::WriteOther ) )
qWarning( "The group or others can change the file" );
See also isReadable(), isWritable(), and isExecutable().
QString QFileInfo::readLink () const
Returns the name a symlink (or shortcut on Windows) points to, or a
QString::null if the object isn't a symbolic link.
This name may not represent an existing file; it is only a string.
QFileInfo::exists() returns TRUE if the symlink points to an existing
file.
See also exists(), isSymLink(), isDir(), and isFile().
void QFileInfo::refresh () const
Refreshes the information about the file, i.e. reads in information
from the file system the next time a cached property is fetched.
See also setCaching().
void QFileInfo::setCaching ( bool enable )
If enable is TRUE, enables caching of file information. If enable is
FALSE caching is disabled.
When caching is enabled, QFileInfo reads the file information from the
file system the first time it's needed, but generally not later.
Caching is enabled by default.
See also refresh() and caching().
void QFileInfo::setFile ( const QString & file )
Sets the file that the QFileInfo provides information about to file.
The file can also include an absolute or relative file path. Absolute
paths begin with the directory separator (e.g. "/" under Unix) or a
drive specification (under Windows). Relative file names begin with a
directory name or a file name and specify a path relative to the
current directory.
Example:
QString absolute = "/local/bin";
QString relative = "local/bin";
QFileInfo absFile( absolute );
QFileInfo relFile( relative );
QDir::setCurrent( QDir::rootDirPath() );
// absFile and relFile now point to the same file
QDir::setCurrent( "/tmp" );
// absFile now points to "/local/bin",
// while relFile points to "/tmp/local/bin"
See also isRelative(), QDir::setCurrent(), and QDir::isRelativePath().
Example: biff/biff.cpp.
void QFileInfo::setFile ( const QFile & file )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Sets the file that the QFileInfo provides information about to file.
If file includes a relative path, the QFileInfo will also have a
relative path.
See also isRelative().
void QFileInfo::setFile ( const QDir & d, const QString & fileName )
This is an overloaded member function, provided for convenience. It
behaves essentially like the above function.
Sets the file that the QFileInfo provides information about to fileName
in directory d.
If fileName includes a relative path, the QFileInfo will also have a
relative path.
See also isRelative().
uint QFileInfo::size () const
Returns the file size in bytes, or 0 if the file does not exist or if
the size is 0 or if the size cannot be fetched.
Example: qdir/qdir.cpp.
SEE ALSO
http://doc.trolltech.com/qfileinfo.html
http://www.trolltech.com/faq/tech.html
COPYRIGHT
Copyright 1992-2007 Trolltech ASA, http://www.trolltech.com. See the
license file included in the distribution for a complete license
statement.
AUTHOR
Generated automatically from the source code.
BUGS
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help you. Thank you.
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If you find errors in this manual page, please report them to qt-
bugs@trolltech.com. Please include the name of the manual page
(qfileinfo.3qt) and the Qt version (3.3.8).
Trolltech AS 2 February 2007 QFileInfo(3qt)